Localized measurement and mapping of tissue nonlinear elasticity

组织非线性弹性的局部测量和绘图

• 批准号: 9196131
• 负责人: Azra Alizad
• 金额: $ 20.99万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9196131
• 关键词: Acoustics; Adipose tissue; Behavior; Benign; Biological Markers; Breast; Clinic; Data; Development; Diagnostic; Diagnostic Imaging; Diagnostic Procedure; Effectiveness; Elasticity; Evaluation; Fibroadenoma; Focused Ultrasound; Future; Geometry; Goals; Histocompatibility Testing; Hydrostatic Pressure; Image; Investigation; Laboratories; Lesion; Magnetic Resonance Imaging; Malignant - descriptor; Malignant Neoplasms; Mammary Gland Parenchyma; Maps; Mass in breast; Measurement; Measures; Mechanics; Medicine; Methodology; Methods; Modality; Monitor; Organ; Outcome; Palpation; Pathologic; Pathology; Performance; Pilot Projects; Property; Publishing; Radiation; Research; Resolution; Sampling; Sensitivity and Specificity; Specificity; Speed; Staging; Techniques; Testing; Time; Tissue Sample; Tissues; Translations; Ultrasonography; Variant; abstracting; animal tissue; base; breast imaging; diagnostic biomarker; elastography; imaging modality; improved; in vivo; infiltrating duct carcinoma; innovation; interest; member; novel; novel diagnostics; physical property; radiation response; response; shear stress; skills; soft tissue; theories; tissue phantom; tool

Abstract Palpation has been used for hundreds of years in medicine to differentiate various types of tissues and masses within tissue. In technical terms, palpation can be defined as deformation of tissue in response to a force, which in linear mechanics is defined as tissue elasticity. The concept of tissue elasticity i.e. elastography has been the subject of intense investigations in the past two decades. However, recent studies have shown that tissue behaves nonlinearly at larger strains, whereby the nonlinear elasticity of tissue may carry important diagnostic information. The long-term objective of this research is the development of a novel diagnostic technique that (i) makes use of the acoustic radiation force (ARF) for noninvasive tissue interrogation, and (ii) deploys a novel coefficient of nonlinear tissue elasticity as a biomarker that is sensitive to tissue type. One possible application of the method, initiated in this study, is the differentiation of breast masses; however, the proposed method may find applications in other organs. The proposed study is made possible by the recent discovery by our research team that the magnitude of the ARF in soft tissues depends linearly on a particular coefficient of nonlinear tissue elasticity, hereon denoted by C – that quantifies the gain in shear wave speed due to increasing hydrostatic pressure. The basic idea behind the method is to act upon tissue by the ARF at a point of interest (e.g. inside a breast mass) and to monitor the ARF-generated generated shear waves via ultrasound. In this setting, the nonlinear modulus C can be computed from the amplitude of the observed shear waves — a claim that is supported by our preliminary data on tissue-mimicking phantoms and animal tissues. The proposed approach to nonlinear tissue elastography is novel in that: (a) it focuses on the volumetric-shear modulus C that has eluded previous studies, and (b) it enables, for the first time, local evaluation of nonlinear tissue elasticity with a spatial resolution given by the size of the focal region (order of mm). This makes it possible to locally measure C over the volume of the focal region using the ARF. For this reason, the proposed method is hereon referred to as nonlinear C-Elastography (CE). To assess the effectiveness of CE, we first propose to create well-characterized phantoms with (tissue-mimicking) lesions and create their C-images to be compared with the respective linear (e.g. shear modulus) elastograms. The last stage of our study would focus on the ex-vivo testing of breast masses, through which we will be able to correlate the CE results to tissue pathology and assess the overall effectiveness of CE. Successful completion of this research will spur the development of a noninvasive, diagnostic tool that may have significant impact in early differentiation of breast masses and potentially pathologies in other organs.

抽象的 触诊在医学上用于区分各种类型的组织和肿块已有数百年历史 组织内。用技术术语来说，触诊可以定义为组织响应力的变形， 在线性力学中被定义为组织弹性。组织弹性的概念，即弹性成像 过去二十年来一直是深入研究的主题。然而，最近的研究表明 组织在较大应变下表现出非线性，因此组织的非线性弹性可能具有重要意义 诊断信息。这项研究的长期目标是开发一种新型诊断方法 (i) 利用声辐射力 (ARF) 进行无创组织询问的技术，以及 (ii) 采用一种新颖的非线性组织弹性系数作为对组织类型敏感的生物标志物。一 本研究中发起的该方法的可能应用是乳腺肿块的区分；然而， 所提出的方法可能会在其他器官中得到应用。最近的研究使拟议的研究成为可能 我们的研究团队发现，软组织中 ARF 的大小与特定的线性相关 非线性组织弹性系数，此处用 C 表示 - 量化剪切波速度的增益 由于静水压力增加。该方法背后的基本思想是通过 ARF 以一定的速度作用于组织。 兴趣点（例如乳房肿块内部）并通过以下方式监测 ARF 生成的剪切波 超声波。在此设置中，非线性模量 C 可以根据观测到的剪切幅值计算得出 波——这一说法得到了我们关于模仿组织模型和动物组织的初步数据的支持。 所提出的非线性组织弹性成像方法的新颖之处在于：（a）它侧重于体积剪切 模量 C，这是以前的研究所回避的，并且 (b) 它首次实现了非线性的局部评估 组织弹性的空间分辨率由焦点区域的大小（毫米级）给出。这使得 可以使用 ARF 局部测量聚焦区域体积上的 C。为此，建议 该方法在此被称为非线性C-弹性成像(CE)。为了评估CE的有效性，我们首先 建议创建具有（模仿组织）病变的特征良好的模型，并创建其 C 图像 与各自的线性（例如剪切模量）弹性图进行比较。我们研究的最后阶段将集中于 乳腺肿块的离体测试，通过该测试我们将能够将 CE 结果与组织相关联 病理学并评估 CE 的整体有效性。这项研究的成功完成将促进 开发一种非侵入性诊断工具，可能对早期分化产生重大影响 乳房肿块和其他器官的潜在病变。